WO2018025567A1

WO2018025567A1 - Battery module

Info

Publication number: WO2018025567A1
Application number: PCT/JP2017/024772
Authority: WO
Inventors: 啓介清水; 曉高野; 慎也本川; 義人加賀; 武史榎本
Original assignee: パナソニックＩｐマネジメント株式会社
Priority date: 2016-08-05
Filing date: 2017-07-06
Publication date: 2018-02-08
Also published as: US20190267686A1; CN109478619A; CN109478619B; JPWO2018025567A1; JP6920660B2; US11380948B2

Abstract

A battery module (10) according to one embodiment of the present invention is provided with: a battery stack (5) that comprises a plurality of first batteries (11A) and a plurality of second batteries (11B), which are alternately stacked; and a thermally conductive member that holds or supports the battery stack (5), while comprising a first member and a second member, which are arranged in the stacking direction of the batteries (11). The first member has a higher thermal resistance to the second batteries (11B) than to the first batteries (11A); while the second member has a higher thermal resistance to the first batteries (11A) than to the second batteries (11B).

Description

Battery module

This disclosure relates to a battery module.

Conventionally, a battery module including a plurality of cylindrical batteries and a battery holder provided with a plurality of battery accommodating portions for accommodating the batteries is known (for example, see Patent Document 1). The battery module disclosed in Patent Document 1 is designed so that the heat capacity of the battery holder is greater on the center side than on the outside of the holder in order to make the temperature of each battery housed in the battery holder uniform.

JP 2012-119136 A

By the way, when some of the plurality of batteries constituting the battery module abnormally generate heat, the heat generated from the battery is easily transferred to other normal batteries, in particular, the battery arranged next to the battery. It is assumed that adjacent batteries also generate abnormal heat due to movement. And thermal damage spreads in a chain in the module, and there is a possibility of causing thermal damage to peripheral devices of the module.

A battery module according to the present disclosure includes a battery assembly including a plurality of first batteries and a plurality of second batteries that are alternately stacked, and a first member and a second member that are respectively provided along the stacking direction of the batteries. The first member has a higher thermal resistance to the second battery than the first battery, and the second member has the first member The thermal resistance of the battery is higher than the thermal resistance of the second battery.

According to the battery module according to the present disclosure, even if some of the batteries mounted on the module abnormally generate heat, the influence on other normal batteries can be reduced, and the chain expansion of thermal damage can be sufficiently suppressed. .

It is a perspective view of the battery module which is 1st Embodiment. It is a top view of the battery module which is 1st Embodiment. It is a figure for demonstrating the function of the battery module which is 1st Embodiment. It is a top view of the battery module which is a modification of 1st Embodiment. It is a top view of the battery module which is another modification of 1st Embodiment. It is a disassembled perspective view of the battery module which is 2nd Embodiment. It is sectional drawing of the battery module which is 2nd Embodiment. It is a figure for demonstrating the function of the battery module which is 2nd Embodiment. It is sectional drawing of the battery module which is a modification of 2nd Embodiment. It is a top view of the cooling plate used for the battery module which is a modification of 2nd Embodiment.

As described above, in a battery module in which a plurality of batteries are mounted, it is an important issue to suppress the chain expansion of thermal damage when some batteries abnormally generate heat. The present inventors solved this problem by using the above-described thermally conductive member. According to the battery module which is one aspect of the present disclosure, the chain expansion of thermal damage can be sufficiently suppressed without causing adverse effects such as an increase in the size of the module, a complicated structure, and an increase in cost.

In the conventional battery module, when some of the batteries generate abnormal heat, the heat is likely to be transmitted to a battery adjacent to the battery that is close in distance. When a heat radiating member having high thermal conductivity is provided, heat is diffused through the heat radiating member, but in this case as well, the amount of heat transfer to the battery disposed adjacent to the abnormal battery increases. According to the battery module according to the present disclosure, it is possible to efficiently release heat from the abnormal battery and to reduce the amount of heat transfer to the battery arranged next to the abnormal battery. Such a decrease in the amount of heat transfer is realized by the thermally conductive member according to the present disclosure.

The heat conductive member according to the present disclosure constructs a structure in which adjacent batteries do not share a heat transfer path. For this reason, although the heat generated in the abnormal battery is diffused and dissipated by the heat conductive member (for example, the first member), the heat transfer to the adjacent battery through the heat conductive member (first member) is greatly increased. It is suppressed. Part of the heat is also transferred to the adjacent battery, but the heat transferred to the adjacent battery is dissipated through a member (second member) having a smaller thermal influence from the abnormal battery through a different path from the abnormal battery. Is done. As described above, since the heat concentration on the battery arranged next to the abnormal battery is alleviated, the expansion of the thermal damage due to the chain of abnormal heat generation can be sufficiently suppressed.

Hereinafter, an example of an embodiment of a battery module according to the present disclosure will be described in detail with reference to the drawings. However, the battery module according to the present disclosure is not limited to the embodiments described below. The drawings referred to in the description of the embodiments are schematically described, and the dimensions of components drawn in the drawings should be determined in consideration of the following description. In the present specification, “substantially to” is intended to include those that are recognized as being substantially constant as well as being completely constant when described as being substantially constant.

Hereinafter, a rectangular battery (battery 11) including a rectangular metal case composed of an outer can and a sealing body will be exemplified as the battery, but the battery is not limited to this. Moreover, although the 1st member and 2nd member which comprise a heat conductive member are demonstrated as what contacts a respectively different battery, they are arrange | positioned so that there may be a difference in thermal resistance (thermal conduction) between adjacent batteries. If so, each member may not be in contact with the battery. In the present specification, “contact” means that two members are in direct contact unless otherwise specified (for example, an adhesive that does not affect thermal conductivity). And the like are present between two members).

<First Embodiment>
The battery module 10 according to the first embodiment will be described in detail below with reference to FIGS. FIG. 1 is a perspective view of the battery module 10, and FIG. 2 is a plan view of the battery module 10.

As illustrated in FIGS. 1 and 2, the battery module 10 includes a battery assembly 5 including a plurality of first batteries 11 A and second batteries 11 B that are alternately stacked, and holds or holds each battery assembly 5. And a thermally conductive member to be supported. A heat conductive member has the 1st member and 2nd member which were each provided along the lamination direction of

battery

11A, 11B. The first member has a higher thermal resistance to the battery 11B than the thermal resistance to the battery 11A, and the second member has a higher thermal resistance to the battery 11A than the thermal resistance to the battery 11B. In other words, heat is more easily transmitted from the battery 11A to the first member than the battery 11B, and heat is more easily transmitted from the battery 11B to the second member than the battery 11A.

As the

batteries

11A and 11B, it is possible to use batteries having different capacities, dimensions, types, etc., but preferably the same battery 11 is used. In the present embodiment, the same batteries are used in different directions, and the

batteries

11A and 11B are arranged such that the lateral positions of the positive and negative terminals are opposite to each other. In this specification, for convenience of explanation, a direction in which the positive electrode terminal 12 and the negative electrode terminal 13 of the battery 11 are arranged is referred to as a “lateral direction”. In addition, the stacking direction of the batteries 11 may be referred to as “vertical direction”.

The battery module 10 further includes a pair of end plates 16 that sandwich the battery assembly 5 composed of a plurality of batteries 11 from both sides in the stacking direction of the batteries 11. In the present embodiment, the heat conductive member is a bind bar 20 that is fixed to each end plate 16 and binds the batteries 11. The bind bar 20 includes a first bar 21 (first member) and a second bar 23 (second member) provided along the stacking direction of the batteries 11. The bind bar 20 binds the batteries 11 together with the end plate 16 to maintain the shape of the battery assembly 5.

The battery 11 includes a battery case composed of a bottomed rectangular tubular outer can 18 having an open upper end and a sealing body 19 that closes the opening of the outer can 18. The battery case is a rectangular metal case, and as described above, the battery 11 is a rectangular battery. The battery 11 is a non-aqueous electrolyte secondary battery such as a lithium ion battery, a nickel-hydrogen battery, or a nickel-cadmium battery, and the outer can 18 includes an electrode body that forms the non-aqueous electrolyte secondary battery and a non-aqueous electrolyte. Contains liquid.

The outer can 18 has a flat shape that is longer in the horizontal direction and the vertical direction (the direction perpendicular to the vertical direction and the horizontal direction) than the vertical direction, particularly in the horizontal direction, but the shape of the outer can is not particularly limited. The outer can 18 is made of, for example, a metal material mainly composed of aluminum, and a resin film is attached to the outer surface of the outer can 18 to ensure insulation. The sealing body 19 is a member for closing the opening of the outer can 18 and sealing the internal space of the battery case, and has a substantially rectangular shape that is long in the lateral direction. For example, the periphery of the sealing body 19 is welded to the peripheral edge of the opening of the outer can 18.

The sealing body 19 is provided with a positive terminal 12 and a negative terminal 13. In the example shown in FIG. 1, in the case of the battery 11 A, the positive electrode terminal 12 is provided at one end in the horizontal direction of the sealing body 19, and the negative electrode terminal 13 is provided at the other end in the horizontal direction. In the case of the battery 11 B, the negative electrode terminal 13 is provided at one end of the sealing body 19 in the horizontal direction, and the positive electrode terminal 12 is provided at the other end in the horizontal direction. For example, through holes are formed in both ends of the sealing body 19 in the lateral direction, and each terminal is attached to each through hole via an insulating gasket.

The battery module 10 has a structure in which a plurality of batteries 11 are stacked in one direction via a plurality of insulating plates 17. An insulating resin film is attached to the outer can 18 of the battery 11, but an insulating plate 17 may be provided between the batteries 11 from the viewpoint of improving the insulating property. In the battery assembly 5, as described above, since the batteries 11 are arranged so that the lateral positions of the positive and negative terminals of the adjacent batteries 11 are opposite to each other, the positive terminal 12 is aligned along the stacking direction of the batteries 11. And negative terminals 13 are alternately arranged.

The battery module 10 includes a bus bar 15 that electrically connects adjacent batteries 11 to each other. In the example shown in FIG. 1, the bus bar 15 connects the positive terminal 12 of the battery 11A and the negative terminal 13 of the battery 11B, and the negative terminal 13 of the battery 11A and the positive terminal 12 of the battery 11B. That is, the batteries 11 mounted on the battery module 10 are connected in series. However, the connection form of each battery 11 is not limited to this. If some of the batteries 11 generate abnormal heat, heat transfer via the bus bar 15 also occurs. However, as will be described later, the influence of such heat transfer is sufficiently mitigated by the bind bar 20.

In the battery module 10, the batteries 11 are bundled by fixing the bind bar 20 to the end plates 16 provided at both ends in the vertical direction and pressing the plates against the battery assembly 5. The end plate 16 is a resin plate, for example, and is formed to be slightly larger than the battery 11. Bolt holes for fastening the bind bar 20 are formed in the end plate 16.

Since the bind bar 20 is fixed to the end plate 16 so as to suppress the expansion of the battery 11 and the end plate 16 is made of a metal such as aluminum, the rigidity of the end plate 16 is insulated from the battery 11 adjacent to the end plate 16. Therefore, an insulating plate 17 is interposed between the end plate 16 and the battery 11 in the same manner as between the batteries 11. When the metal end plate 16 is used, the positive and negative electrode terminals of the battery assembly in which the batteries 11 are integrated are insulated from the end plates 16 at both ends.

As described above, the bind bar 20 has a function of maintaining the binding state of each battery 11 together with the end plate 16 and holding each battery 11. The bind bar 20 includes a first bar 21 provided on one side of the battery assembly 5 along the vertical direction, and a second bar 23 provided on the other side of the battery assembly 5 along the vertical direction. Is done. The first bar 21 and the second bar 23 are arranged so as to sandwich each battery 11 from both sides in the lateral direction, and are preferably arranged to face each other. In the example shown in FIG. 1, a total of four first bars 21 and two second bars 23 are provided, but the number of each bar is not particularly limited. Further, a total of four first bars 21 and two second bars 23 may be provided, one on each side of the battery assembly 5.

Each first bar 21 is provided at the upper part and the lower part of the battery assembly 5 so as to be along the side surface of the battery assembly 5. Similarly, each 2nd bar | burr 23 is each provided in the upper part and the lower part of the battery integration body 5 so that the side surface of the battery integration body 5 may be followed. The first bar 21 and the second bar 23 are, for example, metal plate-like members having a substantially constant width (vertical length), but the thickness (lateral length) is constant as will be described in detail later. Absent. Each bar can be made of resin. In the example shown in FIG. 1, both end portions in the longitudinal direction of each bar are bent so as to wrap around the end surface in the vertical direction of each end plate 16, and the bent portion is bolted to the end plate 16.

As illustrated in FIG. 2, the first bar 21 and the second bar 23 are both in contact with a plurality of batteries 11, but the batteries 11 in contact are different from each other. In the example shown in FIG. 2, the first bar 21 is arranged in contact with each battery 11A, and the second bar 23 is arranged in contact with each battery 11B. On the other hand, the first bar 21 does not contact each battery 11B, and the second bar 23 does not contact each battery 11A. In other words, each battery 11 is in contact with either the first bar 21 or the second bar 23. The first bar 21 and the second bar 23 also function as a heat radiating member that diffuses heat when some of the batteries 11 abnormally generate heat.

Since the first bar 21 contacts the battery 11A and does not contact the battery 11B, the thermal resistance of the first bar 21 to the battery 11B is higher than the thermal resistance of the battery 11A. The heat of the battery 11A is easily transmitted to the first bar 21, and the heat of the battery 11B is difficult to transmit. On the other hand, since the second bar 23 contacts the battery 11B and does not contact the battery 11A, the thermal resistance of the second bar 23 to the battery 11A is higher than the thermal resistance of the battery 11B. The heat of the battery 11B is easily transmitted to the second bar 23, and the heat of the battery 11A is not easily transmitted. In this way, by attaching the bind bar 20, different heat transfer paths are constructed between the adjacent batteries 11.

The first bar 21 has a plurality of protrusions 22 protruding toward the inside (battery 11 side). That is, unevenness is formed on the inner surface of the first bar 21. On the other hand, the outer surface of the first bar 21 is substantially flat. For this reason, the thickness of the 1st bar | burr 21 is changing along the longitudinal direction. Each convex part 22 is formed corresponding to each battery 11A, and each convex part 22 is in contact with the side surface of each battery 11A. Instead of forming the convex portion 22, the first bar can be formed in a waveform.

The convex portions 22 are arranged at equal intervals in the longitudinal direction of the first bar 21. For example, the distance between the protrusions 22 is wider than the distance between the

batteries

11A and 11B (interval between the centers) so that the protrusions 22 are in contact with only the battery 11A. The length (length in the vertical direction) of the portion 22 is made shorter than the thickness (length in the vertical direction) of the battery 11. Thus, regular irregularities are formed on the inner surface of the first bar 21. Each convex part 22 contacts some batteries 11 (battery 11A) every other battery along the vertical direction.

As with the first bar 21, the second bar 23 has a plurality of convex portions 24 projecting inward. The convex portions 24 are arranged at equal intervals in the longitudinal direction of the second bar 23, and regular irregularities are formed on the inner surface of the second bar 23. And each convex part 24 contacts the side surface of some batteries 11 (battery 11B) every other battery along a vertical direction. The pitches, dimensions, and the like of the convex portions of the first bar 21 and the second bar 23 are the same, for example, and the same member as the first bar 21 can be used in the second bar 23 with its orientation changed.

FIG. 3A is a diagram for explaining the function of the battery module 10 having the above configuration, and shows a case where the battery 11AX is abnormally heated. FIG. 3B shows a battery module 100 including a bind bar 101 that contacts all the batteries 11 as a comparative example. When the battery 11AX abnormally generates heat, the heat is transmitted to the adjacent battery 11BY that is closest in distance in both the

battery modules

10 and 100. However, according to the battery module 10, compared with the battery module 100, the amount of heat transfer to the battery 11BY can be greatly reduced, and the thermal influence on the battery 11BY can be reduced.

The battery module 10 has a structure in which adjacent batteries 11 do not share a heat transfer path as described above. As shown in FIG. 3A, the battery 11AX is in direct contact with the first bar 21, but is not in contact with the second bar 23. On the other hand, the battery 11BY is in direct contact with the second bar 23 but is not in contact with the first bar 21. For this reason, the heat generated in the battery 11AX is easily transmitted to the first bar 21 and is diffused and radiated by the first bar 21, but the battery 11BY and the first bar 21 are not in contact with each other. The heat transfer to the battery 11BY is unlikely to occur. In addition, the heat of the battery 11AX is hardly transmitted to the second bar 23 with which the battery 11BY comes into contact.

Since the battery 11BY is in contact with the battery 11AX through the insulating plate 17, it is somewhat affected by the heat generated in the battery 11AX, but the heat transferred to the battery 11BY is applied to the second bar 23, which is less affected by the battery 11AX. The heat can be dissipated through a different path from the battery 11AX. Thus, according to the battery module 10, since the concentration of heat on the battery 11BY is alleviated, the expansion of the thermal damage due to the chain of abnormal heat generation can be sufficiently suppressed.

FIG. 4 is a plan view of a battery module 10Z which is a modification of the first embodiment. As illustrated in FIG. 4, the battery module 10 Z has a low thermal conductivity lower than that of the bind bar 20 between the first bar 21 and the battery 11 B and between the second bar 23 and the battery 11 A. It differs from the battery module 10 in that the member 25 is interposed. The low thermal conductivity member 25 is provided between the convex portions of the first bar 21 and the second bar 23, for example. In this case, since the bar with a low thermal conductivity member contacts the side surfaces of all the batteries 11 and each battery 11 is sandwiched from both sides in the lateral direction, there is an advantage that the binding force of each battery 11 is improved. Also in the battery module 10Z, the concentration of heat to the battery arranged next to the abnormal battery can be alleviated, and the chain expansion of thermal damage can be sufficiently suppressed.

The low thermal conductivity member 25 may be a member having lower thermal conductivity than the bind bar 20, but is preferably a resin member. The low thermal conductivity member 25 is made of, for example, a curable resin. A suitable example of the curable resin is a resin having a cross-linked structure that does not melt even when exposed to a high temperature of 600 ° C. or higher, and carbonizes without melting even when exposed to a high temperature of 800 ° C. to 1000 ° C. The shape of the conductive member 25 is maintained. Specific examples include thermosetting resins such as unsaturated polyesters, epoxy resins, melamine resins, and phenol resins. The curable resin constituting the low thermal conductive member 25 may contain an endothermic filler. The endothermic filler exhibits an endothermic action during thermal decomposition, and specific examples thereof include aluminum hydroxide and sodium hydrogen carbonate. The resin-made low thermal conductivity member 25 is attached to the bind bar 20 using, for example, an adhesive, an adhesive tape, or the like.

FIG. 5 is a plan view of a battery module 10Y which is another modification of the first embodiment. As illustrated in FIG. 5, the battery module 10 Y includes a heat conductive member 26 and a heat insulating member having different heat conductivities between the first bar 21 Y and the battery 11 and between the second bar 23 Y and the battery 11. The battery module 10 differs from the battery module 10 in that the conductive members 27 are alternately interposed. The heat conductive member 26 is provided between the first bar 21Y and the battery 11A, for example, and is provided between the second bar 23Y and the battery 11B. For example, the heat insulating member 27 is provided between the first bar 21Y and the battery 11B, and is provided between the second bar 23Y and the battery 11A. As the heat conductive member 26, a member having the same heat conductivity as each bar or a member having higher heat conductivity than each bar may be used.

Thus, the battery 11A is thermally coupled to the first bar 21Y via the thermal conductive member 26 having good thermal conductivity, and the battery 11B is thermally coupled to the second bar 23Y via the thermal conductive member 26. On the other hand, the battery 11A is thermally insulated from the second bar 23Y by the heat insulating member 27 having a heat conductivity that is much lower than that of the heat conductive member 26, and the battery 11B is insulated from the first bar by the heat insulating member 27. Insulated with 21Y. For this reason, also in the battery module 10Y, the concentration of heat on the battery arranged next to the abnormal battery can be alleviated, and the chain expansion of thermal damage can be sufficiently suppressed.

In addition to the case where the difference in thermal conductivity between the materials of the heat conductive member 26 and the heat insulating member 27 is used, the contact pressure between each bar and the battery 11, the contact area, etc. The thermal conductivity (thermal resistance) may be varied. From the viewpoint of ease of manufacture, it is preferable to use grease bonds having different properties having different thermal conductivities as the thermally conductive member 26 and the heat insulating member 27.

Second Embodiment
The battery module 30 according to the second embodiment will be described in detail below with reference to FIGS. FIG. 6 is an exploded perspective view of the battery module 30. 7 is a longitudinal sectional view of the battery module 30, where FIG. 7A is a sectional view on the first plate 41 side, and FIG. 7B is a sectional view on the second plate 43 side. Below, the same code | symbol is used for the component similar to 1st Embodiment, and the overlapping description is abbreviate | omitted.

As illustrated in FIGS. 6 and 7, the battery module 30 is common to the battery module 10 in that it includes a bind bar 20. On the other hand, the battery module 30 is different from the battery module 10 in that it includes a cooling plate 40 for cooling the battery assembly 5. The cooling method of the cooling plate 40 is, for example, a liquid cooling type in which a liquid refrigerant such as cooling water is circulated inside the plate, but may be an electronic cooling type. In the battery module 30, instead of the bind bar 20, a general bind bar that does not have the

convex portions

22 and 24 and does not contact each battery 11 may be used.

The cooling plate 40 is a heat conductive member that has a first member and a second member respectively provided in the stacking direction of the batteries 11 and holds or supports each battery 11, similarly to the bind bar 20. The cooling plate 40 includes a first plate 41 (first member) and a second plate 43 (second member) provided along the stacking direction of the batteries 11. The first plate 41 and the second plate 43 are arranged below each battery 11 with a gap therebetween. The first plate 41 and the second plate 43 are formed with different paths for flowing the refrigerant, so that the refrigerant flows independently. The first plate 41 and the second plate 43 are Thermally separated.

The battery assembly 5 is placed on the cooling plate 40 and supported by the plate. That is, the plurality of batteries 11 constituting the battery stack 5 are installed on the cooling plate 40, and the bottom surface of each battery 11 is in contact with the cooling plate 40. In addition, the surface which makes each battery 11 which comprises the battery laminated body 5 contact the cooling plate 40 is not limited to the bottom face of each battery 11, and a cooling plate is provided in the side surface of each battery 11 which comprises the battery laminated body 5. You may install so that 40 may contact.

The first plate 41 is provided on one end side in the lateral direction of the battery assembly 5 so as to be along the bottom surface of the battery assembly 5. The second plate 43 is provided on the other lateral end side of the battery assembly 5 so as to follow the bottom surface of the battery assembly 5. The first plate 41 and the second plate 43 are metal plate-like members having a substantially constant width, and the length thereof is longer than that of the battery assembly 5 and corresponds to both longitudinal ends of the battery assembly 5. It extends to both sides in the vertical direction beyond the position. Each plate can be made of resin. In the present embodiment, a cooling plate holder 46 that holds each plate is provided.

As illustrated in FIG. 7, the first plate 41 and the second plate 43 are both in contact with the plurality of batteries 11, but the batteries 11 in contact are different from each other. In the example shown in FIG. 7, the first plate 41 is disposed in contact with each battery 11 A, and the second plate 43 is disposed in contact with each battery 11 B. On the other hand, the first plate 41 does not contact each battery 11B, and the second plate 43 does not contact each battery 11A. In other words, each battery 11 is in contact with either the first plate 41 or the second plate 43.

Since the first plate 41 contacts the battery 11A and does not contact the battery 11B, the thermal resistance of the first plate 41 to the battery 11B is higher than the thermal resistance of the battery 11A. The heat of the battery 11A is easily transmitted to the first plate 41, and the heat of the battery 11B is difficult to transmit. On the other hand, since the second plate 43 contacts the battery 11B and does not contact the battery 11A, the thermal resistance of the second plate 43 to the battery 11A is higher than the thermal resistance of the battery 11B. The heat of the battery 11B is easily transmitted to the second plate 43, and the heat of the battery 11A is not easily transmitted. That is, the cooling plate 40 constructs different heat transfer paths between the adjacent batteries 11.

The first plate 41 has a plurality of recesses 42 that are recessed downward (on the side opposite to the battery 11). That is, unevenness is formed on the upper surface of the first plate 41 on which the battery assembly 5 is placed. On the other hand, the lower surface of the first plate 41 is substantially flat. For this reason, the thickness of the first plate 41 changes along the longitudinal direction. Each recess 42 is provided corresponding to each battery 11B, and a gap is formed between the upper surface of the first plate 41 and each battery 11B. On the other hand, the recess 42 is not provided in the portion corresponding to each battery 11A, and the first plate 41 contacts the bottom surface of each battery 11A. For this reason, it can be said that the convex part which contacts each battery 11A is formed in the part corresponding to each battery 11A.

The recesses 42 are arranged at equal intervals in the longitudinal direction of the first plate 41. For example, the width (vertical length) of each recess 42 is made larger than the thickness of the battery 11 so that the first plate 41 contacts only the battery 11A, and the interval between the recesses 42 is narrower than the interval between the batteries A and 11B. To do. Thus, regular irregularities are formed on the upper surface of the first plate 41. Each recess 42 forms a gap with every other battery 11 (each battery 11B) along the vertical direction, and the first plate 41 of each battery 11A is not provided with the recess 42. Touch the bottom. Since the bottom surface of the battery 11 B is lifted from the first plate 41 at the portion where the recess 42 is formed, a part of the bottom surface of the battery 11 B may be placed on the cooling plate holder 46.

As with the first plate 41, the second plate 43 has a plurality of recesses 44 that are recessed downward. The concave portions 44 are arranged at equal intervals in the longitudinal direction of the second plate 43, and regular irregularities are formed on the upper surface of the second plate 43. And each recessed part 44 forms a clearance gap between some batteries 11 (each battery 11A) every other battery along a vertical direction, and the 2nd plate 43 is each battery in the part in which the recessed part 44 is not provided. It contacts the bottom surface of 11B. The pitches, dimensions, and the like of the concave portions of the first plate 41 and the second plate 43 are, for example, the same. For the second plate 43, the same member as the first plate 41 can be used with its orientation changed.

FIG. 8A is a diagram for explaining the function of the battery module 30 having the above-described configuration, and shows a case where the battery 11AX is abnormally heated. FIG. 8B shows a battery module 110 including a cooling plate 111 that contacts all the batteries 11 as a comparative example. The function of the bind bar 20 is as described above, and a description thereof is omitted here. When the battery 11AX abnormally generates heat, the heat is transmitted to the adjacent battery 11BY that is closest in distance in both the

battery modules

30 and 110. However, according to the battery module 30, compared with the battery module 110, the amount of heat transfer to the battery 11BY can be greatly reduced, and the thermal influence on the battery 11BY can be reduced.

The battery module 30 has a structure in which adjacent batteries 11 do not share a heat transfer path as described above. As shown in FIG. 8A, the battery 11AX is in direct contact with the first plate 41, but not in contact with the second plate 43. On the other hand, the battery 11BY is in direct contact with the second plate 43, but not in contact with the first plate 41 (see FIG. 7). For this reason, the heat generated in the battery 11AX is easily transmitted to the first plate 41, and is diffused and radiated by the first plate 41. However, since the battery 11BY and the first plate 41 are not in contact with each other, the heat passes through the first plate 41. The heat transfer to the battery 11BY is unlikely to occur. In addition, the heat of the battery 11AX is not easily transmitted to the second plate 43 with which the battery 11BY comes into contact.

Since the battery 11BY is in contact with the battery 11AX via the insulating plate 17, it is somewhat affected by the heat generated in the battery 11AX, but the heat transferred to the battery 11BY is applied to the second plate 43 that is less affected by the battery 11AX. The heat can be dissipated through a different path from the battery 11AX. Thus, according to the battery module 30, since the heat concentration on the battery 11BY is alleviated, it is possible to sufficiently suppress the expansion of the thermal damage due to the chain of abnormal heat generation.

FIG. 9 is a cross-sectional view of a battery module 30Z that is a modification of the second embodiment. As illustrated in FIG. 9, the battery module 30 Z has low thermal conductivity that is lower than the cooling plate 40 between the first plate 41 and the battery 11 B and between the second plate 43 and the battery 11 A. It differs from the battery module 30 in that the member 45 is interposed. The low heat conductive member 45 is provided in each recessed part of each plate, for example. In this case, since the plate with a low thermal conductivity member is in contact with the bottom surfaces of all the batteries 11, there is an advantage that the supportability of each battery 11 is improved. Also in the battery module 30Z, the concentration of heat on the battery arranged next to the abnormal battery can be alleviated, and the chain expansion of thermal damage can be sufficiently suppressed. The low thermal conductivity member 45 is made of the same material as the low thermal conductivity member 25 described above.

FIG. 10 is a plan view of a cooling plate 40Y used in a battery module that is a modification of the second embodiment. In FIG. 10, the battery 11 disposed on the cooling plate 40Y is indicated by a two-dot chain line. As illustrated in FIG. 10, the first plate 41 Y and the second plate 43 Y are formed in a comb shape so as to mesh with each other with a gap so that the tooth portions of the comb do not contact each other. The first plate 41Y and the second plate 43Y have different paths through which the refrigerant flows, so that the refrigerant flows independently. The first plate 41Y and the second plate 43Y Thermally separated. In the example shown in FIG. 10, the comb tooth portions of the first plate 41Y and the second plate 43Y are formed corresponding to the positions of the batteries 11A and the batteries 11B, respectively, and matched to the bottom shape of each battery 11. It has a different shape. The first plate 41Y and the second plate 43Y may be connected to each other by a connecting member 47.

In the present embodiment, the plurality of batteries 11 constituting the battery stack 5 are installed on the cooling plate 40Y, but the surface that makes each battery 11 constituting the battery stack 5 contact the cooling plate 40Y. Is not limited to the bottom surface of each battery 11, and the cooling plate 40 Y may be placed in contact with the side surface of each battery 11 constituting the battery stack 5. Also in this case, the comb teeth of the first plate 41Y and the second plate 43Y are formed corresponding to the positions of the batteries 11A and the batteries 11B, respectively. The comb teeth of the first plate 41Y and the second plate 43Y have a shape that matches the shape of the side surface of each battery 11.

Both the first plate 41Y and the second plate 43Y are in contact with a plurality of batteries 11 every other battery for each battery 11 constituting the battery stack 5. The first plate 41Y is disposed in contact with each battery 11A, and the second plate 43Y is disposed in contact with each battery 11B. On the other hand, the first plate 41Y does not contact each battery 11B, and the second plate 43Y does not contact each battery 11A. Therefore, the battery module using the cooling plate 40Y has a structure in which the adjacent batteries 11 do not share the heat transfer path. For this reason, the thermal resistance of the first plate 41Y to the battery 11B is higher than the thermal resistance of the battery 11A, while the thermal resistance of the second plate 43Y to the battery 11A is higher than the thermal resistance of the battery 11B. That is, the cooling plate 40Y constructs different heat transfer paths between the adjacent batteries 11.

<First Embodiment>
5 battery assembly, 10 battery module, 11, 11A, 11B battery, 12 positive terminal, 13 negative terminal, 15 bus bar, 16 end plate, 17 insulating plate, 18 outer can, 19 sealing body, 20 bind bar, 21 1st Bar, 22, 24 Convex part, 23 Second bar, 25 Low thermal conductivity member, 26 Thermal conductivity member, 27 Thermal insulation member <Second embodiment>
30 battery module, 40 cooling plate, 41 first plate, 42, 44 recess, 43 second plate, 45 low thermal conductivity member, 46 cooling plate holder, 47 connecting member

Claims

A battery assembly including a plurality of first batteries and second batteries stacked alternately;
A heat conductive member having a first member and a second member respectively provided along the stacking direction of the batteries, and holding or supporting the battery assembly;
With
The first member has a higher thermal resistance to the second battery than a thermal resistance to the first battery,
The second member is a battery module in which a thermal resistance with respect to the first battery is higher than a thermal resistance with respect to the second battery.
A pair of end plates sandwiching the battery stack from both sides in the battery stacking direction;
The thermally conductive member is a bind bar fixed to the end plates and for binding the batteries, wherein the first member is in contact with the first battery, and the second member is The battery module according to claim 1, wherein the battery module is disposed in contact with each second battery.
The thermally conductive member is a cooling plate for cooling the battery assembly, wherein the first member is in contact with each first battery, and the second member is in contact with each second battery. The battery module according to claim 1, wherein the battery modules are arranged in a state where the battery modules are placed in a closed state.
A low thermal conductive member having lower thermal conductivity than the thermal conductive member is interposed between the first member and the second battery, and between the second member and the first battery. The battery module according to any one of claims 1 to 3, wherein:
4. The battery module according to claim 3, wherein the first member and the second member of the cooling plate are formed with different paths for flowing a refrigerant in the first member and the second member, respectively.